[NFS] write performance depends on root_squash/no_root_squash - NFS

This is a discussion on [NFS] write performance depends on root_squash/no_root_squash - NFS ; Dear all,
Could you kindly help me with this please:
1. Case 1:
Export options on the NFS server:
"/exports/default" *(rw,no_root_squash)
>From the same NFS client, the root user can write files very fast, but
a normal user incredibly slow.
...